Wheel dressing device



Sept. 3, 1957 L. o. CARLSEN ET AL 2,804,867

WHEEL. DRESSING DEVICE Original Filed Aug. 24. 1953 2 Sheets-Sheet 1 JNVENTORS LEONARD O. CARLSEN BY EARL D. DAMMERT A T TORIVEY Sept. 3, 1957 1.. o. CARLSEN ET AL WHEEL DRESSING DEVICE Original Filed Aug. 24. 1953 2 Sheets-Sheet 2 F'IG.4

- -1NVENT0R$ LEONARD o. CARLSEN EARL D. DAMMERT ATTORMY' tates WHEEL DRESSING DEVICE Leonard 0. Carlsen, Rochester, and Earl D. Damniert,

Penfield, N. Y., assignors to The Gleason Works, Rochester, N. Y., a corporation of New York 12 Claims. (Cl. 125-11) The present invention relates to a dresser for an abrasive wheel or the like, for example for the abrasive wheel of a cutter sharpening machine; and is a division of our application Serial No. 375,870, filed August 24, 1953, for a Cutter Sharpening Machine.

According to the invention the dresser comprises a housing and a dressing tool carrying arm mounted thereon for swinging motion to carry the tool across the related abrasive wheel for dressing the latter, spring means to urge motion of said arm in one direction, dash-pot means to retard such spring-urged motion and thereby control the velocity of the dressing motion, and latch means to releasably hold the arm in its limit position of motion in the direction opposite to such spring-urged motion.

In the preferred form of the invention the arm is pivoted and is operated by a manually cocked spring at a rate controlled by hydraulic dash-pot means. To cock the mechanism a handle connected to the arm is swung to its limit position in one direction, and to effect the dressing stroke this same handle, now serving as a trigger, is moved a perpendicular direction. The rate of the dressing stroke may be varied by adjustable valve means in the dash-pot system in order to dress the wheel surface to the desired texture.

A typical embodiment of the invention is shown in the accompanying drawings, wherein:

Fig. 1 is a plan view of a cutter sharpening machine with the dresser mounted thereon;

Fig. 2 is a side view of the dresser, partly in elevation and partly in section in the plane indicated by line 2-2 of Fig. 3;

Fig. 3 is a cross-sectional view through the dresser in the plane 33 of Fig. 2, and;

Fig. 4 is a detail sectional view taken approximately in the plane indicated by section line 4- 1 of Fig. 2.

The machine shown in Fig. 1 comprises a support for a cutter C to be sharpened by an abrasive wheel W, the latter being rotatable in a wheel head 11 which is mounted on a support 12 for oscillation about axis 13 so that the wheel is passed back-and-forth across the front faces of the cutter blades. The wheel is dressed periodically and for this purpose is swung about axis 13 to a position clear of the cutter, and is held in this position, which is shown in broken lines, during the dressing operation. The dresser includes an arm 14 which carries a dressing tool taking the form of a diamond D, the arm being mounted on a rock shaft 15 that is journaled on anti-friction bearings 16 in a dresser housing 17. This housing is mounted on the wheel head support 12 for adjustment thereon to such position that when the wheel is in the broken line position, Fig. l, the arcuate path 18 of the tool D about the axis of shaft 15 is substantially radial of the wheel at a mean point on the wheels active surface. With this arrangement the active surface of the wheel may be dressed to an almost exactly conical shape.

The dressing stroke of the arm 14, clockwise in Figs. l and 3, is effected by a coiled compression spring 19 moving a plunger 21 that is slidable in the housing, the plunger atent having rack teeth meshing with teeth 22 on the shaft.

The assembly comprising the spring and plunger and arm is cocked for its dressing stroke by turning the shaft counterclockwise by means of a handle 23 which is pivoted to the shaft by a transverse pin 24; and the assembly,-

is held cocked by abutment of a pin 25 on the handle with a pin 26 carried by the housing. The handle carries a spring-backed plunger 27 which constantly urges it about the axis of pin 24, in a counterclockwise direction in Fig. 2, to maintain the pins 25, 26 in abutting relation. To effect the dressing stroke after the assembly has been cocked, the operator need only push the handlev 23 about the. axis of pin 24, to the broken line position of the handle shown in Fig. 2. This releases the pin 25 from abutment with pin 26 and allows the spring 19 to move the assembly through its dressing stroke.

The velocity of this stroke, which determines the texture of the surface dressed on the rotating wheel W, is controlled by hydraulic dash-pot means. For this purpose the interior of the housing, including the cylinder chamber 28, and also the opposite cylinder chamber which opens into bore 29 in the end of the plunger 21, is filled with hydraulic fluid. The passage in the plunger connecting bore 29 with chamber 28 is closed by a spring-pressed ball check valve 31 arranged to open to freely pass fluid from the bore to the chamber and to close to prevent fluid flow in the opposite direction. However fluid displaced from chamber 28 by the spring-urged motion of plunger 21 passes to the opposite cylinder chamber" These ports respectively open through passages 42 and- 43 into the cylinder chamber that includes bore 29. Passage 42 is partially obstructed by a spring-locked adjustable plug valve 44 that is adjusted topermit a fairly fast flow of fluid, while passage 43 is obstructed partially by a similar valve 45 adjusted to permit a slower flow of fluid.

The rotary valve 37 has a handle 46 by which it may be turned on screw 35 between opposite limit positions that are determined by abutment of a pin 47 on the housing with the ends of an arcuate recess 48 on the inner face of the valve. When handle 46 is turned counterclockwise to its limit position shown in Fig. 2 valve passage 38 is aligned with port 39 and hence the dressing stroke of the diamond will be fairly fast, as is normally wanted to produce a coarse finish on the wheel for a rough grinding or sharpening operation. If the handle is turned to its opposite limit position, as at 46', in Fig. 2, passage 38 is aligned with port 41 and hence the dressing stroke is slower and will produce a finer finish on the wheel, such as is normally wanted for finish sharpening a cutter. If the handle is turned to its central position, shown by broken lines 46" in Fig. 2, valve passage 38 does not register with either of ports 39 and 41. Hence no fluid can pass from chamber 28 and therefore the dressing stroke is prevented. In this connection it will be understood that at least in some cases, as for example where the cutter blade edges are badly chipped, it may be desirable to rough sharpen all of the blades around the cutter one or more times to remove the damaged stock, and then to finish sharpen all of the blades.

Having now described the dresser which constitutes the preferred embodiment of the invention, and the method of operation and the use of the dresser, what we claim as our invention is:

l. A dresser for an abrasive wheel comprising a hous- Paten s 3 1951- ing and an arm having a dressing tool mounted thereon, the arm beingmounted' on the housing for swinging motion to carry the tool across-the wheel for dressing the latter spring meansto urge motion of said arm in one directiongdash-pot means to retard such spring-urged handle being-movable relative to the arm to release said latch means.

3 A dresser according to claim 1 in which thereis a handle pivoted to the arm about an axis perpendicular to the axis of swinging motion, and the latch means comprises abutments on the housing and handle, said. abutments when engaged witheach other holding the handle and arm against said swinging motion, and spring means for urging the handle about its pivot axis to retain said abutments engaged.

4. A dresser according to claim I in which the dashpot means includes a plunger reciprocable in the housing and connected to the. arm to effect swinging of the arm, andin which the spring means acts between the housing and the plunger.

5, A dresser according to claim 4 in which there is a fluid chamber in which the plunger reciprocates, means for controlling the rate of discharge from the chamber of fluid displaced by the plunger during the spring-urged motion thereof, and a check valve arranged to opento freely admit fluid to the chamber during: motion of the plunger in the opposite direction.

6. A dresser according to claim 5 in which the means for controlling the rate of discharge includes a manually operable valve for varying the rate of the discharge.

7. A grinding machine having an abrasive wheel, a dresser on the machine comprising a housing and an arm having a dressing tool mounted thereon, the arm being mounted on the housing for swinging motion to carry the tool across the wheel for dressing the latter, spring means to urge motion of said arm in one direction, dash-pot means to retard such spring urged motion and thereby control the velocity of the tool during its motion across the wheel, and latch means to releasably hold the arm in its limit position of motion in the direction opposite to such spring-urged motion.

8. A grinding machine according to claim 1 in which there is a handle for moving the arm in said opposite direction, said handle being movable relative to the arm to release said latch means.

9. A grinding machine according to claim 1 in which there is a handle pivoted to the arm about an axis perpendicular to the axis of swinging motion, and the latch means comprises abutments on the. housing and handle, said abutrnents when engaged with each other holding the handle and arm against said swinging motion, and spring means for urging the handle about its pivot axis to retain said abutments engaged.

10. A grinding machine according to claim 1 in which the dash-pot means includes a plunger reciprocable in the housing and connected to the arm to etfect swinging of the arm, and in which the spring means acts between the housing and the plunger.

11. A grinding machine acording to claim 10 in which there is a fluid chamber in which the plunger reciprocates, means for controlling the rate of discharge from the chamber of fluid displaced by the plunger during the spring-urged motion thereof, and a check valve arranged to open to freely admit fluid to the chamber during motion of the plunger in the opposite direction.

12. A grinding machine accordingv to claim 11 in which themeans for controlling the rate of discharge includes a manually operable valve for varying the rate of the discharge.

References Cited in the file of this patent UNITED STATES PATENTS Carlsen Nov. 21, 1944 ar -Am 

